URL
https://opencores.org/ocsvn/openrisc_me/openrisc_me/trunk
Subversion Repositories openrisc_me
[/] [openrisc/] [trunk/] [gnu-src/] [gcc-4.5.1/] [gcc/] [testsuite/] [gcc.dg/] [noncompile/] [label-1.c] - Rev 319
Go to most recent revision | Compare with Previous | Blame | View Log
/* Test various diagnostics of ill-formed constructs involving labels. */ /* { dg-do compile } */ /* { dg-options "-Wunused" } */ extern void dummy(void); /* labels must be defined */ void a(void) { goto l; /* { dg-error "used but not defined" "no label" } */ } /* warnings for labels defined but not used, or declared but not defined */ void b(void) { __label__ l; l: /* { dg-warning "defined but not used" "no goto 1" } */ m: /* { dg-warning "defined but not used" "no goto 2" } */ dummy(); } void c(void) { __label__ l; /* { dg-warning "declared but not defined" "only __label__" } */ dummy(); } /* can't have two labels with the same name in the same function */ void d(void) { l: dummy(); /* { dg-message "note: previous definition" "prev def same scope" } */ l: dummy(); /* { dg-error "duplicate label" "dup label same scope" } */ goto l; } /* even at different scopes */ void e(void) { l: dummy(); /* { dg-message "note: previous definition" "prev def diff scope" } */ { l: dummy(); /* { dg-error "duplicate label" "dup label diff scope" } */ } goto l; } /* but, with __label__, you can */ void f(void) { l: dummy(); { __label__ l; l: dummy(); /* { dg-warning "defined but not used" "unused shadow 1" } */ }; goto l; /* this reaches the outer l */ } /* a __label__ is not visible outside its scope */ void g(void) { dummy(); { __label__ l; l: dummy(); goto l; } goto l; /* { dg-error "used but not defined" "label ref out of scope" } */ } /* __label__ can appear at top level of a function, too... ... but doesn't provide a definition of the label */ void h(void) { __label__ l; dummy (); goto l; /* { dg-error "used but not defined" "used, only __label__" } */ } /* A nested function may not goto a label outside itself */ void i(void) { auto void nest(void); l: nest(); void nest(void) { goto l; /* { dg-error "used but not defined" "nest use outer label" } */ } goto l; /* reaches the outer l */ } /* which means that a nested function may have its own label with the same name as the outer function */ void j(void) { auto void nest(void); l: nest(); void nest(void) { l: dummy(); /* { dg-warning "defined but not used" "nest label same name" } */ } goto l; /* reaches the outer l */ } /* and, turnabout, an outer function may not goto a label in a nested function */ void k(void) { void nest(void) { l: dummy(); /* { dg-warning "defined but not used" "outer use nest label" } */ } goto l; /* { dg-error "used but not defined" "outer use nest label" } */ nest(); } /* not even with __label__ */ void l(void) { void nest(void) { __label__ l; l: dummy(); /* { dg-warning "defined but not used" "outer use nest __label__" } */ } goto l; /* { dg-error "used but not defined" "outer use nest __label__" } */ nest(); } /* but if the outer label is declared with __label__, then a nested function can goto that label (accomplishing a longjmp) */ void m(void) { __label__ l; void nest(void) { goto l; } nest(); dummy(); l:; } /* and that means the nested function cannot have its own label with the same name as an outer label declared with __label__ */ void n(void) { __label__ l; /* { dg-message "note: previous declaration" "outer label decl" } */ void nest(void) { l: goto l; /* { dg-error "duplicate label" "inner label defn" } */ } l: nest(); } /* unless the nested function uses __label__ too! */ void o(void) { __label__ l; void nest(void) { __label__ l; l: goto l; } l: goto l; nest(); }
Go to most recent revision | Compare with Previous | Blame | View Log